HTML In Custom Fields

This isn’t a Buddypress specific question but I know there are some really smart dudes on here that would know the answer. I setup up a special custom field box for people to past Vimeo video code, which uses an iframe. The problem is this textarea then tries to render the iframe/html after the post has been saved, instead of showing the raw html. Is there a way to stop the html from rendering like how WordPress’s html post tab does? Thanks.